New API required to convert existing replica 2 volumes to thin-arbiter

[itisravi]

We would need a new API/ gd2 command to convert existing replica 2 volumes to thin-arbiter. An example of the current syntax for creating TA volumes is:

glustercli volume create testvol 192.168.122.159:/bricks/brick1 192.168.122.159:/bricks/brick2 --replica 2 --thin-arbiter 192.168.122.207:/bricks/brick_ta

Based on this we could either do an add-brick based API or a volume set based option. I think add-brick or a similar CLI is better:

Eg: gluster volume add-ta $volname $ta_host:$ta_brick_path

That would also be in line with converting say a replica 3 volume to TA volume by doing a remove-brick and then add-ta

[itisravi]

@aravindavk @amarts @karthik-us @aspandey

[amarts]

Can this be a option like glustercli volume set $vol thin-arbiter $ta-host:$ta_brick_path ? That way, this will be a volgen option to add a volume (like shard option), and fits in existing APIs itself ?

[itisravi]

Can this be a option like glustercli volume set $vol thin-arbiter $ta-host:$ta_brick_path

We could do this,but wondering if it will cause confusion for new volume creations . i.e. does a user try glustercli volume create or do they first create a replica 2 and then set this option.

[aravindavk]

We could do this,but wondering if it will cause confusion for new volume creations . i.e. does a user try glustercli volume create or do they first create a replica 2 and then set this option.

In glustercli we are doing the same but does volume create and setting options together. (https://github.com/gluster/glusterd2/blob/master/glustercli/cmd/volume-create.go#L299-L314)